Piston ring



NOV. l2, 1940.. R PATON I 2,220,948 Y Nov. 12, 1940. R. w. PATON l PISTON RING Filed Jail. 5, 1933 2 Sheets-Shea?l 2 Patented Nov. 12, 1940 y y i UNITED STATES PATENT OFFICE PISTON RING Roy W. Paton, Hagerstown, Ind., assignor to The Perfect Circle Company, Hagerstown, Ind., a corporation of Indiana Application January 3, 1939, Serial No. 249,035

15 Claims. (Cl. 309-45) My invention relates to piston rings adapted and upon which the railsections are seated t to be mounted in the ring groove in a piston of an support the same in axially spaced relation, and internal combustion engine havingacylinder Wall the expander section having spring portions to be engaged by the ring, and it has to do paradapted to engage the body portion of the carrier ticularly with segmental rings of the foregoing section through a substantial contact area for character adapted for reducing oil consumption; applying expanding pressure to the rail sections.

One of the objects of myinvention is to pro- Other objects and advantages will become apvide an' improved ring of the foregoing character parent as this description progresses and by ref- Which is of simple construction, and which is erencetothe drawings wherein,-

adapted to perform its intended functionsy in a Figure 1 is a horizontal sectional view taken 10 highly -ecient manner, and particularly when through the ring groove of a piston having ring applied to pistons used in worn cylinders. structure embodying my invention mounted Another object is to provide a segmental ringv therein; f including a pair of thin, split, ring-like steel Vrail Fig. 2 is an enlarged sectional view of the strucsections supported both radially and in axially ture shown vin Fig. 1, the same being illustrated 15 spaced relation by a split steel Aring-like carrier in position inacylinder; l section that is engaged and radially expanded to Fig. 3 is an assembly view of the ring strucexpand the rail sections by a spring `steel exture showninFigs. 1 and 2; pander section adapted to be mounted in the ring Fig. 4 is a fragmentall side elevational view of groove behind the carrier section, the sections the ring structure shown in the previous gures, 20 being so constructed and arranged that the carvand further illustrating the manner of inter' `rier section extends substantially throughout the locking certain of the ring sections; and inner edges of the rail sections and engages such Fig. 5 is a fragmental, perspective view of a edges over the greater portion thereof, the ex modified form of carrier section that may be pander section engages only the carrier section employed in carrying out my invention.

and in such a Way that the spring contact area The ring structure shown in the drawings is effective on the rail sections is increased, and the adapted to be mounted in the groove I0 (Figs. 1 expanding pressure exerted on the rail sections and 2) in the piston II, of an internal combustion is substantially equalized throughout the circum- Y engine having a cylinder I2 in which the piston ference thereof. operates. The piston II may take any suitable 30 A further object is to provide ring structure of form and it is provided with an annular series of the foregoing character wherein the rail and caroil holes I3 leading through the piston wall from. rier sections form an oil channel extending subthe bottom 'of the ring groove I0 for drainage of stantially throughout the Width of the rail secoil from the latter back to the engine crank case tions and opening outwardly toward the cylinder (not shown). The ring structure that I have 35 wall, the rail sections being supported by the carchosen to illustrate my invention is of segmental rier section in such a Way that drainage of oil form and it includes a pair of rail sections I4, from the ring channel through the ring structure I5 (Figs. 1-3), a carrier section I6 and an extakes place along (over and under) the opposite pander section I1. l

40 sides of each of the rail sections. The rail sections Ill and I5 (Fig. 3), which are 40 Still another object is to provide a segmental of similar construction, are each formed from a ring including a pair of split, thin, steel rail seclthin steel material to a ring-like shape split at tions spaced apart axially and supported radially I8 for purposes that will -be Well understood. by a split steel carrier section which is interlocked These sections are adapted to be disposed along with the rail sections in such a way that the rail the opposite side walls of the ring groove I0 and' 45 and carrier sections expand and contract, or they are of such width that, when a piston embreathe, S0 t0 Speak, as alunit. bodying the same is inserted in the cylinder I2,

A more specic object is to provide a segmental they engage the -cylinder Wall I22| (Fig. 2) under ring structure including split, ring-like, thin rail some tension. The rail sections I4, I5 are supsections, a carrier section and an expander secported in axially spaced position, as Well as 50 tion, the carrier section including a split, bandradially, by the carrier section IB, which will now like steel body portion disposed behind the rail be described.` sections with its side edges engaging the inner The carrier section I6, which is located behind edges of the rail sections and having projectionsthe rail sections I4, I5, takes the form of an an- 5 struck. therefrom outwardly of the ring structure nular band having a body portion IIa that is split 55 at I9. This section i's formed from a relatively thin steel material and it is of such width that it extends substantially throughout the width of the ring groove I so that its opposite side edges engage the inner edges of the rail sections I4, I5, and thereby support the rail sections I4, I in radial direction. The carrier section I6 is further provided with an annular row of circumferentially spaced supporting lugs struck therefrom along the opposite or upper and lower edges thereof, the lugs 20 being so formed that those of the upper row are staggered relative to the adjacent lugs of the lower row. The lugs 20, which are of less length than the width of the rail sections I4, I5 and which extend outwardly of the) ring .groove IIJ in a plane substantially parallel with the oppositel side walls of the ring groove and the sides of the rail sections I4 and I5, engage the inner sides of the rail sections I4 and I5 to support the latter in` axially spaced-apart position. The lugs 20 are, preferably, located inwardly of the side edges of the carrier body I6a a distance substantially equal to the thickness of the rail sections so that ,the rail sections are supported adjacent the sides of the ring groove I0 with a slight clearance. Also, the lugs 20 are comparatively narrow and they are so spaced apart that a substantial and major portion of the carrier body I6a extends behind and engages the inner edges of the rail sections I4, I5 providing an increased and quite substantial radial support therefor.

As is well known, a piston ring tends to expand and contract, or breathe, so to speak, as the piston supporting it reciprocates in a cylinder, and particularly a worn cylinder where the diameter of the cylinder varies because of wear. This breathing action tends to cause a piston ring to creep or shift circumferentiallyin its groove and, in the use of a segmental ring, it causes the several segments or sections thereof to tend to creep rela' tive to each other. It is desirable that for best performance, the ring sections, or certain of them, be prevented from creeping; and, in carrying out my invention, I so construct and arrange the rail and carrier sections that they will expand and contract, or breathe, as a unit. To that end, the carrier body ends I9 and I'Ib formed by the carrier slit I9 are provided with outturned right-angular lugs 2|, 22 so located that the lug 2| is at the end of the upper row of rail supporting lugs 20 and the other lug 22 is at the other end of the lower row of lugs 20. One end of the upper rail section I4 abuts the lug 2| andthe opposite end of the lower-rail 'section abuts the lug 22. With this arrangement, when the piston II is mounted in the cylinder I2 and the rail and carrier sections are contracted to working diameter, the ends' of the rail section are disposed in such close proximity to the respective lugs 22, 2| that no material relative displacement of the rail and carrier sections can take place in a circum- -ferential direction. It will be noted that the rail sections I4, I5 of somewhat greater diameter than the carrier section I6 so that, when the rail sections are properly assembled with the carrier section and such sections are contracted to working diameter, the joint I8 of one rail is slightly offset circumferentially from the joint I8 of the other rail. This arrangement not only facilitates the sealing action of the ring but also aids thel interlock feature above referred to.

When the rail and spacer sections I4, I5 and I6 are assembled, they` provide a continuous, an-

vacequia nular oil channel 23 of a. depth substantially equal to the depth of the ring and opening outwardly through the outer face of the ring structure. Oil scraped from the cylinder wall I2a into the channel 23 is drainedL radially through the ring structure and back to the engine crank case through the piston holes I3 by passing over and under the rail sections and, in part, through the openings 2I|a provided in forming the lugs 20 and, in part, past the side edges of the carrier body IGH. As a piston embodying my ring structure reciprocates in a cylinder, a hydraulic action takes place in which oil tends to be thrown, forced or pumped, so to speak, toward the opposite side walls of the ring groove, and it is at these points that oil drainage is afforded by my ring structure. In other words, in carrying out my invention, there is suiicient clearance between the rails I4, I5 and the adjacent side walls of the ring groove I0 to permit oil collected in the oil channel 23 to readily pass the ring structure under the infiuence of the hydraulic action above referred to,

even though the carrier I6 may not be provided' with drain openings for that purpose. However, if desired, a perforated carrier section, asshown in Fig. 5, may be employed. In thatcase, the carrier section 24 may be provided with small openings 25 formed therein opposite each rail supporting lug 26 thereof.

The expander section I'I takes the form of a thin, split, polygonally shaped band of spring steel, the corners IIIl of which form spring humps. 'I'he expander portions I1b between the humps IIa are adapted to seat against the inner wall of the ring groove I0, while the humps I'I engage the' inner side of the carrier section body I6a at substantially equally spaced points around the circumference thereof. When the expander is assembled in the ring groove along with the other ring sections, it tends constantly to urge the carrier section outwardly, in turn, simultaneously and uniformly expanding the rail sections I4 and I5 supported by the carrier section I6. With this arrangement, the expandingaction transmitted from the expander section I1 through the carrier section I6 to the rail sections I 4,I5 is equalized and uniformly distributed throughout the circumference of the rail sections without concentration of-the same at points opposite the humps II. Also, the expander contact area is increased tending to minimize wear, and the entire arrangement is such that the structure may expand and contract freely and tendency of the expander to collapse during high-speed operation is reduced to the minimum.

The expander section I'I is further provided with cil drainage recesses 21 disposed along the opposite side edges thereof. The recesses 2'I in one edge of the expander section are staggered relative to the recess 21 in the opposite expander edge, but such recesses are of such length that the ends of adjacent recesses overlap. 'I'he recesses 21 are located substantially in alignment with the rail sections I4, I5 adjacent the sides of the ring groove Ill, thereby facilitating oil drainage past the expander section I'I under the iniluence of the hydraulic action above referred to. I believe that the operation and advantage of my invention will be well understood from the foregoing description; and, while I have illustrated only two forms of my invention, other changes in details and arrangements of parts may be resorted to withoutdeparting from my invention as dened by the claims that follow.

1. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine having a cylinder wall to be engaged by the ring structure, which comprises a. pair of thin, split, ring-like rail sections adapted to be mounted in spaced relation adjacent the sides of the ring groove, a split carrier section having a bandlike body portion disposed in a plane behind said rail sections with its opposite edge portions seated against and radially supporting the inner edges of said rail sections, said carrier'l body portion having axially spaced portions extending therefrom between and axially supporting said rail sections, and an expander section disposed behind said carrier section and having spring portions engaging only the body portion of said carrier section to expand said rail sections.

2. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine having a cylinder wall to be engaged by the ring structure, which comprises a pair of thin, split, ring-like rail sections adapted to be mounted in spaced relation adjacent the sides of the ring groove, a split carrier section having a. bandlike body portion disposed in a plane behind said rail sections with its opposite edge portionsl seated against and radially supporting the inner'.

edges of said rail sections, and forming with said rail sections a continuous oil channel opening outwardly toward the cylinder wall to he engaged and of a depth substantially equal to the width of said rail sections, said carrier body portion having portions extending therefrom between and axially supporting said rail sections, and an expander section disposed behind said carrier section andhaving spring portions engaging only said carrier section to expand said rail sections.

3. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine having a cylinder wall to be engaged by the ring structure, which comprises a pair of thin,

split, ring-like rail sections, a carrier section disposed behind said rail sections with its opposite side edges engaging the inner edges of the latter for radial support thereof, said carrier section having spaced upper and lower rows\of lugs between its opposite side edges and extending inwardly between and supporting said rail sections in axially spaced relation adjacent the sides ofthe ring groove, and means located behind and engaging said carrier section for applying radial expanding pressure thereto to, in turn, radially expand said rail sections.

4x Piston ring structure adapted for use in the ringgroove in a piston of an internal combustion engine havingv a cylinder wall to be engaged by the ring structure, which comprises a pairof thin, split, ring-like rail sections, a carrier section of band-like form disposed behind said rail sections with its opposite side edges'engaging the inner edges of the' latter for radial support thereof, said carrier section having spaced upper and lower annular rowsof circumierentially spaced lugs between its side edges and extending inwardly between and supporting said rail sections in axially spaced relation adjacent the sides of the groove,` said lugs being of a length lass than the'"'width of said rail sections with the lugs of one row staggered relative to the lugs of the other row, and means located behind and engaging said carrier section for applying radial expanding pressure thereto to, in turn, radially expand said rail sections.

5. Piston ring structure adapted for use inthe ring groove in a piston oi an internal. combustion engine having a cylinder wall to be 1engaged by the ring structure, which comprises a. pair of thin, split, ring-like rail sections, a carrier section of band-like form disposed in a plane behind said rail sections with its opposite side edges engaging the inner edges of said rail sections, said carrier section having portions of its opposite edges displaced inwardly between said rail sections and engaging the adjacent faces of the latter to support them in axially spaced relation adjacent the sides of the ring groove, and an expander section engaging only said carrier sections to apply radial expanding pressure thereto and, in turn, to saidrail sections.

6. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine having a cylinder wall to be engaged by the ring structure, which comprises a pair of thin, split, ring-like rail sections, a carrier section of band-like form and of a width only slightly less than the width of the ring groove and disposed in a plane behind said rail sections with its opposite side edges engaging the inner edges of said rail sections, said carrier section having portions of its opposite edges displaced inwardly between said rail sections and engaging the adjacent faces:

of the latter to support them in axially spaced relation adjacent the sides of the ring groove, said portions being disposed in annular rows axially 7. Piston ring structure adapted for use in the 4 ring groove in apiston of an internal combustion engine having a cylinder wall to be engaged by the ring structure, which comprises a pair of split, ring-like rail sections having outer edges adapted to engage the cylinder wall, a band-like carrier section disposed in a plane behindsaid rail sections with its opposite side edges engaging the inner edges of said rail sections to radially support the latter and to form` with said rail sections a continuous, annular oil channel, said carrier section having portions adjacent the opposite edges thereof extending inwardly and between said rail sections to support the same Vin axially spaced relation, said carrier section being of such width that ithas substantially a working clearance with respect to the opposite sides oi the ring groove, and said rail supporting portions beingso .disposedand saidirail sections being of such thickness that said rails are supported with substantially the same working 4clearance as said carrier section, the arrangement being such thatl oil passes from said channel to the back of the ring groove only along the opposite sides of each of said rail sections, and an expander section engaging only said carrier section yto apply expanding pressure thereto and to said edges of said rail sections to radially support the latter, portions extending from the opposite side edge portions of said carrier section between said rail sections for axially supporting and spacing 5 them apart relative -to the sides of the ring groove, said rail sections and that portion of the carrier section between said rail sections providing an imperforate-walled annular oil channel opening outwardly toward the cylinder wall, the arrangement being such that oil can pass from said channel to the back of -the ring groove only along the opposite sides of each of said rail sections, and an expander section adapted to be mounted in the ring groove behind said carrier section to engage and expand the latter and, in turn, said rail sections.

9. Piston ring structure adapted for use in the` ring groove in a piston of an internal combustion engine having a cylinder wall to be engaged by the ring structure, which comprises a pair of thin, split rail sections adapted to be mounted adjacent the sides of the ring groove, a split carrier sec-tion having portions disposed behind and engaging the inner edges of said rail section to support the latter radially, said carrier section having other portions extending between said rail sections and supporting the same in axially spaced relation, an interlock element on said carrier section and engaged by one of said rail sections, another interlock element on said carrier section and engaged by the other of said rail scctions independently of the first-mentioned interlock element, said elements preventing any substantial relative circumferential movement between said carrier and rail sections in circum ferential direction only, whereby all said sections expand and contract as a unit.

10. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion 40 engine having a cylinder wall to be engaged by the ring structure, which comprises a pair of thin, split rail sections adapted to be mounted adjacent the sides of the ring groove, a split carrier section having portions disposed behind and en- 45 gaging the inner edges of said rail section to support the latter radially, said carrier section having other portions extending between said rail sections and supporting the same in axially spaced relation, an interlock element on one of 50 the split ends of said carrier section circumferentially aligned with the upper of said rail sections and adapted to be abutted by ythe split ends of vsuch rail section, another interlock element on the other split end of said carrier section cir- 55 cumferentially aligned with the lower of said rail sections and adapted to be abutted by the split ends of such rail section, the arrangement being such that all said sections are interlocked together to expand and contract as a unit, and an ex- 30 pander section for applying expanding pressure to said unit.

11. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine, which comprises a pair of thin rail sec- 65 tions adapted to be mounted adjacent the sides of the ring groove, each of said rail sections being split providing free ends, a split carriersection having portions disposed behind and engaging the inner edges of said rail sections to support the 70 latter radially, said carrier section having other portions extending between said rail sections and supporting the same in axially spaced relation, an interlock element on said carrier section and disposed between the free ends of one of said rail 'I5 sections, another and axially offset interlock element on said carrier section and disposed between the free ends of the other of said rail sections, said interlock elements preventing any substantial relative movement between said carrier and rail sections in circumferential direction only, whereby all said sections expand and contract as a unit.

12. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine, which comprises a pair of thin, split rail sections adapted to be mounted adjacent the sides of the ring groove, a split carrier section having portions disposed behind and engaging the inner edges of said rail section to support the latter radially, said carrier section having other portions extending between said rail sections and supporting the same in axially spaced relation, an interlock element on one of the split ends of said carrier section circumferentially aligned with the upper of said rail sections and adapted to be disposed between thesplit ends of such rail section, another interlock element on the other split end of said carrier section circumferentially aligned with the lower of said rail sections and adapted to be disposed 'between the split ends of such rail section, the arrangement being such that all said sections are linterlocked together to expand and contract as a unit. v

13. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine, which comprises a pair of thin, split rail sections adapted to be mounted adjacent the sides of the ring groove, a split carrier section having portions disposed behind and engaging the inner c edges of said rail sections to support the latter radially, said carrier section having other portions extending between said rail sections and supporting the same in axially spaced relation,`

and means providing an interlock between said rail and carrier sections for preventing relative circumferential movement therebetween which comprises a portion extending at substantially right angles from each of the split ends of said carrier section, one of said right-angular portions extending between the split ends of one of said rail sections and `the other of said right-angular portions extending between the split ends of the other of said rail sections.

.4. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine, which comprises a pair of thin, split rail sections adapted to be mounted adjacent the sides of the ring groove, a split carrier section having portions disposed behind and engaging the inner edges of said rail sections to support the latter radially, said carrier section having other portions extending between said rail sections and supporting the same in axially spaced relation, and means providing an interlock between said rail and carrier sections for preventingA relative circumferential movement therebetween which comprises a portion extending at substantially right anglrs from each of the split ends of saidl 15. Piston ring structure adapted for use in the ring groove in a piston of an internal combustion engine, which comprises a pair of thin, split rail sections adapted to be mounted adjacent the sides of the ring groove, a split, band-like carrier section having portions disposed behind and engaging the inner edges of said rail sections to support the latter radially, said carrier section having other portions with surfaces disposed axially inward of the side edges of the section which are disposed between said rail sections for supporting them in axially spaced relation, and another edgewise portion extending eritwardl:v at substantially right angles at each of the split ends of said sections.

carrier section. one of said edgewise portions extending Irom the upper edge of said carrier section and terminating short of the lower edge thereof a distance suicient to permit the lower rail section to pass the same, and the other of said edgewise .portions extending from the lower edge of said carrier section and Iterminating short of the upper edge thereof sufficiently to permit the upper rail section to pass the same, said edgewise portions being disposed, respectively, between the split ends of the upper and lower of said rail ROY W. PATON. 

